Nontrauma helicopter emergency medical services transport: annotated review of selected outcomes-related literature

While helicopter emergency medical services (HEMS) has its roots in military transport of wounded soldiers, rotor-wing transport is also used for a wide variety of nontrauma indications. Despite this common use of HEMS for noninjured patients, a Medline search found little systematic review of the literature pertinent to HEMS use for nontrauma. With HEMS utilization subject to appropriately increased scrutiny, those seeking to research HEMS utility in noninjured patients could benefit from existence of a collection of the topical literature. This paper aims to provide such a review, in the form of an annotated bibliography of Index Medicus journal studies assessing potential medical risks and benefits of HEMS transport for noninjured patients. The paper's goal is to provide a useful resource for those interested in pursuing more focused review of various sectors of the nontrauma HEMS literature. As such, the main objective of the article summaries is to provide a brief outline of study design and results; there is also limited editorial comment included after each summary.

First Record of Meloidogyne partityla on Pecan in Georgia

In July 2000, tree decline was observed in a commercial pecan (Carya illinoensis (Wang.) K. Koch) orchard in Crisp County, GA. Most affected trees exhibited dead branches in the upper canopy, stunted growth, and feeder roots with small galls and associated egg masses typical of root-knot nematode infection. All declining trees that were examined had root systems infected with a Meloidogyne sp. Efforts to culture the nematode on tomato (Lycopersicon esculentum Mill. 'Rutgers') were unsuccessful. Identification of the nematode was determined by two laboratory procedures in March 2001. Female nematodes were teased from fresh pecan root galls of declining trees in Georgia, and identified by determining the esterase phenotype from replicate samples of single females compared with standard root-knot nematode species, including a population of M. partityla (3). Galled roots also were sent to New Mexico State University in Las Cruces, where mitochondrial DNA from specimens was extracted and compared with that from standard root-knot nematode species and known populations of M. partityla (2). Specimens had esterase phenotypes and DNA patterns consistent with M. partityla. Esterase phentoypes were inconsistent with M. incognita and M. arenaria, and DNA patterns were inconsistent with M. incognita, M. javanica, and M. hapla. Specimens at both locations were identified as M. partityla Kleynhans (1). To our knowledge, this is the first report of M. partityla from Georgia and the third report of this nematode outside of South Africa. The first and second report of M. partityla from pecan in the United States occurred in Texas and New Mexico in 1996 and 2001, respectively (3,4). Our inability to culture the M. partityla-GA isolate on tomato substantiates previous experience with this nematode in the United States (3) and is not surprising, since this species has a host range limited to the Juglandaceae. Furthermore, M. partityla may be endemic to North America and not South Africa. It is believed this nematode entered South Africa on pecan seedling roots imported from the United States between 1912 and 1940 (1). The unusually narrow host range may explain why M. partityla has gone unrecognized for so long in the United States compared with the more common Meloidogyne spp. (i.e., M. incognita and M. arenaria) with wider host ranges found in pecan orchards. Determining the distribution of M. partityla within the major pecan-growing regions of Georgia and throughout North America is warranted. References: (1) K. P. N. Kleynhans. Phytophylactica 18:103, 1986. (2) T. O. Powers and T. S. Harris. J. Nematol. 25:1, 1993. (3) J. L. Starr et al. J. Nematol. 28:565, 1996. (4) S. H. Thomas et al. Plant Dis. 85:1030, 2001.

Helicopter transport and blunt trauma mortality: a multicenter trial

BACKGROUND

Despite many studies addressing potential impact of helicopter transport on trauma mortality, debate as to the efficacy of air transport continues.

METHODS

This retrospective study combined trauma registry data from five urban Level I adult and pediatric centers. Logistic regression assessed effect of helicopter transport on mortality while adjusting for age, sex, transport year, receiving hospital, prehospital level of care (Advanced Life Support vs. Basic Life Support), ISS, and mission type (scene vs. interfacility).

RESULTS

The study database comprised 16,699 patients. Crude mortality for Air (9.4%) was 3.4 times (95% CI, 2.9-4.0, p < 0.001) that of Ground (3.0%) patients. In adjusted analysis, helicopter transport was found to be associated with a significant mortality reduction (odds ratio, 0.76; 95% CI, 0.59-0.98; p = 0.031).

CONCLUSION

The results of this study are consistent with an association between helicopter transport mode and increased survival in blunt trauma patients.

Hyperventilation in traumatic brain injury patients: inconsistency between consensus guidelines and clinical practice

BACKGROUND

This study assessed patients with traumatic brain injury (TBI) to determine whether prehospital and community hospital providers employed hyperventilation therapy inconsistent with consensus recommendation against its routine use.

METHODS

This prospective analysis of 37 intubated TBI patients without herniation, undergoing helicopter transport to an urban Level I center, entailed flight crews' noting of assisted ventilation rate (AVR) and end-tidal carbon dioxide (ETCO2) upon their arrival at trauma scenes or community hospitals. A priori-set levels of AVR and ETCO2 were used to assess frequency of guideline-inconsistent hyperventilation, and Fisher's exact and Kruskal-Wallis tests assessed association between guideline-inconsistent hyperventilation and manual vs. mechanical ventilation mode.

RESULTS

Inappropriately high AVR and low ETCO2 were seen in 60% and 70% of patients, respectively. Manual ventilation was associated with guideline-inconsistent hyperventilation assessed by AVR (p = 0.038) and ETCO2 (p = 0.022).

CONCLUSION

Prehospital and community hospital hyperventilation practices are not consistent with consensus recommendations for limitation of hyperventilation therapy.

First Report of Meloidogyne partityla on Pecan in New Mexico

For several years, decline was observed in mature pecan (Carya illinoensis (F.A. Wangenheim) K. Koch) trees in an orchard in Dona Ana County, New Mexico despite normal fertilization and irrigation practices. Affected trees were growing in sandy soil in two widely separated irrigation terraces and exhibited chlorosis of foliage and substantial die-back of branches in the upper canopy. Examination of feeder roots revealed the presence of numerous small galls and egg masses, with root-knot nematode females often visibly protruding from root tissue. Attempts to culture the nematode on tomato (Lycopersicon esculentum Mill. 'Rutgers') were unsuccessful. Females and egg masses were collected from fresh pecan roots and sent to the USDA Nematology Laboratory in Beltsville, MD, in October 2000, where specimens were identified as Meloidogyne partityla Kleynhans (1) based on morphological examination. This is the first report of M. partityla from New Mexico, and the second report of this nematode outside South Africa. Starr et al. (2) first reported M. partityla from pecan in the United States in 1996, after recovering the nematode from five orchards in Texas. In their study, the host range of M. partityla was limited to members of the Juglandaceae, which may explain the inability of the New Mexico population to reproduce on tomato. Additional information is needed regarding distribution of this nematode within pecan-growing regions throughout North America. References: (1) K. P. N. Kleynhans. Phytophylactica 18:103, 1986. (2) J. L. Starr et al. J. Nematol. 28:565, 1996.

First Report of Columbia Root-Knot Nematode (Meloidogyne chitwoodi) in Potato in New Mexico

Following a report of Columbia root-knot nematode in potatoes (Solanum tuberosum L.) imported by Mexico from the United States in spring 2000, six fields in San Juan County, NM, were surveyed in August 2000. Soil samples from two fields in which the exported potatoes had been produced contained second-stage juveniles that were tentatively identified as Columbia root-knot nematode. During the 2000 potato harvest, state inspectors detected tubers from four additional fields that exhibited symptoms of Columbia root-knot nematode, including warty exteriors and discrete small brown lesions that were apparent to a depth of 1 cm below the tuber surface. Meloidogyne chitwoodi Golden et al. (1) was confirmed from a subsample of tubers sent to the USDA Nematology Laboratory in Beltsville, MD, in October 2000. Identification was based on morphological examination of the nematodes recovered from tubers. To our knowledge, this is the first report of M. chitwoodi from New Mexico. No Columbia root-knot nematodes were recovered from soil samples collected at 26 locations throughout San Juan County in 1988 and 1989, nor had symptomatic tubers or plants been observed in this area previously. Columbia root-knot nematode most likely represents a recent introduction into northwestern New Mexico. Additional information regarding distribution of this nematode within the region is needed. References: (1) A. M. Golden et al. J. Nematol. 12:319-327, 1980.

Anti-TNF agents for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory, autoimmune disease with a prevalence of approximately 1% and an annual incidence of 0.04%. Up to 50% of patients with RA are unable to work 10 years after diagnosis. The disease is associated with significant morbidity and mortality with associated medical costs to the UK of between £240 m and £600 m per year.

Non steroidal anti-inflammatory drugs (NSAIDs) have little effect on the underlying course of RA, but they have some anti-inflammatory and analgesic properties. Disease modifying antirheumatic drugs (DMARDs) have been shown to slow progression of RA and are currently recommended early in the course of treatment of RA which is when disease progression is most rapid.

Etanercept and infliximab belong to a new group of parentally administered antitumour necrosis factor (TNF) drugs.

Etanercept is licensed in the UK for the treatment of active rheumatoid arthritis in patients who have not responded to other DMARDs and in children with polyarticular-course juvenile arthritis who have not responded to or are intolerant of methotrexate. In adults it produces significant improvements in all measures of rheumatic disease activity compared to placebo. In patients whose disease remains active despite methotrexate treatment, further improvement in control is obtained with the addition of etanercept without an increase in toxicity. In one small trial, etanercept was found to be more effective than placebo in a selected group of children.

Infliximab is a monoclonal antibody which is currently licensed in the UK for Crohn's disease and, in combination with methotrexate for the treatment of rheumatoid arthritis in patients with active disease when the response to disease-modifying drugs, including methotrexate, has been inadequate. In clinical trials infliximab produced significant improvements in all measures of rheumatic disease activity compared with placebo. Infliximab in combination with methotrexate was shown to be superior to methotrexate or infliximab alone.

There are currently no predictors of a good response to anti-TNF drugs and a percentage of patients fail to respond to treatment (25% to 38% of etanercept patients; 21% to 42% of infliximab patients). Infliximab monotherapy induces the production of anti-infliximab antibodies, which may reduce its effectiveness. Adding methotrexate to infliximab therapy may prevent this response.

Anti-TNF drugs may affect host defences against infection and malignancy; whether these agents affect the development and course of malignancies and chronic infections is unknown and safety and efficacy in patients with immunosuppression or chronic infections has not been investigated. With infliximab, upper respiratory tract infections, general infections and those requiring antimicrobial treatment were more common in patients than placebo. Likewise, upper respiratory tract infections were more common in patients treated with etanercept than with placebo. Injection site reactions occur with both infliximab (16%–20%) and etanercept (37%).

There are approximately 600 000 patients with RA in the UK, and of these between 2% and 3.5% may have severe disease which has failed to respond to conventional treatment and who might be eligible for anti-TNF therapy. If between 50% and 70% of patients treated with anti-TNF drugs respond and continue on long-term treatment then the recurrent annual cost to the NHS could be between £48 m and £129 m .

Etomidate versus succinylcholine for intubation in an air medical setting

The objective was to compare rates of successful endotracheal intubation (ETI) and requirement for multiple ETI attempts in patients receiving etomidate (ETOM) versus succinylcholine (SUX). This retrospective study analyzed adults in whom oral ETI was attempted by a helicopter EMS (HEMS) service between July 1997 to July 1999. Data were from records of the HEMS service, which uses a RN/EMTP crew; analysis was with chi-square and logistic regression (P = .05). ETI was successful in 269 (97.8%) of 275 patients, with multiple attempts occurring in 54 (20.1%) of 269. Success rates for SUX (209 of 213, 98.1%) and ETOM (60 of 62, 96.8%) were similar (P = .62). However, of 60 ETOM patients successfully intubated, 7 (11.7%) required rescue succinylcholine. When these patients are tallied as ETOM failures and SUX successes, resultant success rates for ETOM (86.9%) and SUX (98.2%) are different (P = .001). ETOM patients were more likely (P = .004) than SUX patients to require multiple attempts (33.3% versus 16.3%). ETI success rates were high in patients receiving SUX or ETOM as primary adjuncts for airway control, but initial success was more likely with SUX, and ETOM patients were more likely to require multiple attempts.

Appropriateness of endotracheal tube size and insertion depth in children undergoing air medical transport

OBJECTIVES

Guidelines for pediatric endotracheal tube (ETT) size and insertion depth are important in the helicopter EMS (HEMS) setting, where intubated patients are frequently transported by a non-physician flight crew providing protocol-based care in an environment noted for limitations in clinical airway assessment. The objectives of this study were to characterize, in a HEMS pediatric population, the frequency of compliance with guideline-recommended ETT size and insertion depth, and to test for association between guideline noncompliance and subsequent receiving hospital adjustment of ETT size or insertion depth.

DESIGN

This retrospective review analyzed 216 consecutive pediatric (age <14) scene and interfacility HEMS transports, of patients intubated before or during HEMS transport, by an urban two-helicopter HEMS service providing protocol-based care with a nurse/paramedic crew configuration. Patients were transported to one of three receiving academic pediatric referral centers. Pediatric Advanced Life Support (PALS) criteria for ETT size and insertion depth were used to assess guideline-appropriateness of pediatric ETTs. Receiving hospital records were reviewed to determine if post-transport ETT size or lipline adjustment were associated with guideline-appropriateness of size and lipline during HEMS transport. Univariate (chi-square and Fisher's exact) and multivariate (logistic regression) statistics were used to assess and control for the following covariates: intubator group (physician, flight crew, ground EMS), transport year, sex, age, transport type (scene versus interfacility), and receiving hospital. For all analyses, statistical significance was set at the 0.05 level.

RESULTS

The initial ETT size was within 0.5 mm of guideline-recommended sizes in 178 (83.6%) of the 213 patients for whom this data were available. Inappropriate sized ETTs were nearly always (32 of 35, 91.4%) too small. Compared to initial ETTs placed by ground EMS personnel, initial ETTs placed by flight crew or physicians were more likely to be appropriate as defined by guidelines (P = .008 and .032, respectively). Receiving hospitals changed the ETT size in 18 (8.3% of 216) cases. Receiving hospital ETT size change was more likely with later transport year (P = .018) and less likely in patients over 2 years of age (P = .03); there was no significant association between receiving hospital ETT size change and intubator group (P > .22) or guideline-appropriateness of ETT size (P = 0.94). The initial ETT insertion depth was within 1 cm of the guideline-recommended lipline in 86 (43.2%) of the 199 patients for whom this data were available. Inappropriate liplines were almost always (109 of 113, 96.5%) too deep. Compared to initial ETT liplines determined by ground EMS personnel, initial liplines determined by flight crew (P = .007), but not physician (P = .47) were more likely to be appropriate as defined by guidelines. Receiving hospitals changed the ETT insertion depth in 72 (33.3% of 216) cases. Receiving hospital lipline change was more likely (P = .03) in patients older than 2 years of age, but was not associated with intubator group (P = .75) or lipline guideline-appropriateness (P = .35).

CONCLUSIONS

As judged by frequently used guidelines, pediatric ETTs are often too small and commonly inserted too deep. However, this retrospective study, limited by lack of clinical correlation for ETT size and insertion depth, failed to find an association between lack of ETT size or lipline guideline compliance and subsequent ETT adjustment at receiving pediatric centers. This study's findings, which should be confirmed with prospective investigation, cast doubt upon the utility of pediatric ETT size/lipline guidelines as strict clinical or quality assurance tools for use in pediatric airway management.

Helicopter emergency medical services roles in disaster operations

Rotor-wing aircraft have previously proven utility in disaster operations, but recent expert reviewers have identified areas of potential improvement in integration of helicopter emergency medical services (HEMS) resources into disaster planning and management. This paper discusses salient points regarding helicopter operations in disaster management, using prior reports regarding rotor-wing aircraft utilization as a basis upon which to provide a concise review of HEMS operations in disasters.

Reduction in incidence of severe paracetamol poisoning

We report substantial reductions in the frequency of severe paracetamol hepatotoxicity locally and nationally after legislative limitations on its sale. These reductions were not explained by changes in referral patterns or use of N-acetylcysteine.

QTc-interval abnormalities and psychotropic drug therapy in psychiatric patients

BACKGROUND

Sudden unexplained death in psychiatric patients may be due to drug-induced arrhythmia, of which lengthening of the rate-corrected QT interval (QTc) on the electrocardiogram is a predictive marker. We estimated the point prevalence of QTc lengthening in psychiatric patients and the effects of various psychotropic drugs.

METHODS

Electrocardiograms were obtained from 101 healthy reference individuals and 495 psychiatric patients in various inpatient and community settings and were analysed with a previously validated digitiser technique. Patients with and without QTc lengthening, QTc dispersion, and T-wave abnormality were compared by logistic regression to calculate odds ratios for predictive variables.

FINDINGS

Abnormal QTc was defined from the healthy reference group as more than 456 ms and was present in 8% (40 of 495) of patients. Age over 65 years (odds ratio 3.0 [95% CI 1.1-8.3]), use of tricyclic antidepressants (4.4 [1.6-12.1]), thioridazine (5.4 [2.0-13.7]), and droperidol (6.7 [1.8-24.8]) were robust predictors of QTc lengthening, as was antipsychotic dose (high dose 5.3 [1.2-24.4]; very high dose 8.2 [1.5-43.6]). Abnormal QT dispersion or T-wave abnormalities were not significantly associated with antipsychotic treatment, but were associated with lithium therapy.

INTERPRETATION

Antipsychotic drugs cause QTc lengthening in a dose-related manner. Risks are substantially higher for thioridazine and droperidol. These drugs may therefore confer an increased risk of drug-induced arrhythmia.

Frequency and costs of laboratory and radiograph repetition in trauma patients undergoing interfacility transfer

Receiving trauma centers often duplicate laboratory and radiograph testing performed by referring institutions. Our objective was to quantify frequency and costs of this practice. In this prospective study of 104 consecutive interfacility-transported adult trauma patients flown by an emergency medical service to an urban level I center, flight crew noted which labs and radiographs were done at referring hospitals, which tests were sent with patients, and which were repeated on trauma center arrival. Overall, results from 246 of 283 (86.9%) laboratory tests and 241 of 249 (96.8%) radiographs done at referring hospitals were sent with patients. Repetition of laboratory tests at the receiving hospital was frequent regardless of whether initial results were sent (P = .6 by chi2), and radiograph repetition was unrelated to whether sent films were originals or copies (P = .2 by chi2). For these 104 patients, the receiving hospital charged $66,463 for repetition of work-up done at referring facilities.

Effectiveness of delayed activated charcoal administration in simulated paracetamol (acetaminophen) overdose

AIMS

Oral activated charcoal is used to treat drug overdose and is effective at reducing drug absorption when administered within 1 h of drug ingestion. There are fewer data on efficacy when the delay is longer, as is the case in most drug overdoses. This study investigated the efficacy of activated charcoal at preventing paracetamol (acetaminophen) absorption after simulated overdose when administration was delayed between 1 and 4 h.

METHODS

An open randomized-order four-way crossover study was performed in healthy volunteers comparing the effect of activated charcoal 50 g on the absorption of 3 g paracetamol tablets when administered after an interval of 1, 2 or 4 h or not at all. Plasma paracetamol concentrations were measured over 9 h after paracetamol ingestion using h.p.l.c. and areas under the curve between 4 and 9 h (AUC(4,9 h)) calculated as a measure of paracetamol absorption.

RESULTS

Activated charcoal significantly reduced paracetamol AUC(4,9 h) when administered after 1 h (mean reduction 56%; 95% Confidence intervals 34, 78; P<0.002) or 2 h (22%; 6, 39; P<0.03) but not after 4 h (8%; -8, 24). When administered after 1 h activated charcoal reduced individual plasma paracetamol concentrations significantly at all times between 4 and 9 h after paracetamol administration. Administration at 2 or 4 h had no significant effect.

CONCLUSIONS

These results in healthy volunteers cannot be extrapolated directly to poisoned patients. However, they provide no evidence of efficacy for activated charcoal when administered after an interval of more than 2 h.

Congenital anomalies after prenatal ecstasy exposure

Prospective follow-up of 136 babies exposed to ecstasy in utero indicated that the drug may be associated with a significantly increased risk of congenital defects (15.4% [95% CI 8.2-25.4]). Cardiovascular anomalies (26 per 1000 livebirths [3.0-90.0]) and musculoskeletal anomalies (38 per 1000 [8.0-109.0]) were predominant.

Flight crew airway management in four settings: a six-year review

OBJECTIVE

To analyze flight crew airway management in four different settings (in flight, at trauma scenes, in ambulance, and in referring hospitals) and in two different aircraft used by the same helicopter EMS (HEMS) service. The null hypothesis was that there was no association between practice setting, or aircraft, and airway practices or success rate.

METHODS

This retrospective study analyzed all patients in whom advanced airway management was attempted by the HEMS service during the study period October 1991 through October 1997. Data used were from flight records of Boston MedFlight Critical Care Transport Service, which uses a nurse/paramedic crew and had a paralytic-assisted intubation protocol in place. Data were analyzed with chi-square and Fisher's exact testing, risk ratio analysis, and logistic regression.

RESULTS

Advanced airway management was attempted in 722 patients, with an airway placed in 705 (97.8%). Intubation success was unrelated to site of airway management (p = 0.14), but patients were more likely to have intubation attempted prior to flight (as opposed to in flight) if the crew were in the AS365N2 Dauphin as compared with the BK-117 (p<0.0001). In addition, patients were 0.77 times as likely (95% confidence interval, 0.68-0.88) to receive paralytic-facilitated intubation if airway management occurred in the hospital setting as compared with other sites.

CONCLUSIONS

While HEMS crew airway management success rates are equally high in all practice settings, airway management decision making and practice appear to be significantly influenced by practice setting and aircraft type. These data support contentions that nonphysician HEMS crews can effectively manage airways in a variety of circumstances.

Patient and physician agreement on abdominal pain severity and need for opioid analgesia

Whereas controversy surrounds emergency department (ED) analgesia administration to patients with undifferentiated abdominal pain, few studies have addressed the level of patient-physician agreement on abdominal pain severity and need for opioid analgesia. This prospective study was undertaken to assess concordance between emergency physicians and patients on abdominal pain severity. Study subjects were a convenience sample of 30 adults seen in an urban university-affiliated tertiary care ED (annual census 65,000) who had undifferentiated abdominal pain meeting an initial severity threshold of 5 on a 10 cm visual analog scale (VAS) marked by the patient. Patients' and physicians' VAS scores, obtained in blinded fashion at presentation (t0) and at one (t1) and two (t2) hours into the ED stay, were compared with t test (VAS scores) and sign-rank (percent change in VAS scores) analyses. In addition, patients and physicians were asked at each assessment time, in blinded fashion, "Is the pain severe enough to warrant morphine?" The kappa statistic was used to characterize the degree of agreement between physician and patient assessments as to whether opioids were indicated. At t0, t1, and t2, patients' mean VAS scores (7.5, 6.7, and 5.1) were significantly (P < .05) higher than the corresponding physicians' VAS scores (5.3, 4.7, and 3.9). Though VAS scores for physicians started lower than those of patients, the percentage changes in scores from one assessment to the next were similar by Wilcoxon sign-rank testing (P > .50 for time intervals t0 - t1 and t1 - t2). Overall, patients and physicians agreed on the question of whether pain was sufficient to warrant opioids in 71 of 90 (78.9%) assessments; the corresponding kappa statistic of .57 indicated moderate agreement (P < .0001). These results, indicating that patients and physicians usually agree on whether opioids are warranted for abdominal pain, have important implications for further research on ED analgesia in this population.

The use of atypical antipsychotics in the management of schizophrenia

Long-term drug treatment of schizophrenia with conventional antipsychotics has limitations: an estimated quarter to one third of patients are treatment-resistant; conventional antipsychotics have only a modest impact upon negative symptoms (poverty of thought, social withdrawal and loss of affect); and adverse effects, particularly extrapyramidal symptoms (EPS). Newer, so-called atypical, antipsychotics such as olanzapine, risperidone, sertindole and clozapine (an old drug which was re-introduced in 1990) are claimed to address these limitations. Atypical agents are, at a minimum, at least as effective as conventional drugs such as haloperidol. They also cause substantially fewer extrapyramidal symptoms. However, some other adverse effects are more common than with conventional drugs. For example, clozapine carries a significant risk of serious blood disorders, for which special monitoring is mandatory; it also causes troublesome drowsiness and increased salivation more often than conventional agents. Some atypical agents cause more weight gain or QT prolongation than older agents. The choice of therapy is, therefore, not straightforward. At present, atypical agents represent an advance for patients with severe or intolerable EPS. Most published evidence exists to support the use of clozapine, which has also been shown to be effective in schizophrenia refractory to conventional agents. However, the need for compliance with blood count monitoring and its sedative properties make careful patient selection important. The extent of any additional direct benefit offered by atypical agents on negative symptoms is not yet clear. The lack of a depot formulation for atypical drugs may pose a significant practical problem. To date, only two double-blind studies in which atypical agents were compared directly have been published. Neither provides compelling evidence for the choice of one agent over another. Atypical agents are many times more expensive than conventional drugs. Although drug treatment constitutes only a small proportion of the costs of managing schizophrenia, the additional annual cost of the use of atypical agents in, say, a quarter of the likely U.K. schizophrenic population would be about 56 M pound sterling. There is only limited evidence of cost-effectiveness. Atypical antipsychotics are not currently licensed for other conditions where conventional antipsychotics are commonly used, such as behaviour disturbance or dementia in the elderly. Their dose, and place in treatment in such cases have yet to be determined.

Air vs ground transport and outcome in trauma patients requiring urgent operative interventions

OBJECTIVE

To study trauma patients requiring urgent operative interventions to determine whether transport mode was associated with outcome difference.

METHODS

Eligible patients were injured adults and children who presented over a 57-month period to the emergency department (ED) at the study hospital (annual ED census 36,000) after air or ground transport from trauma scenes or referring hospitals. Patients included were those whose ED lengths of stay were <60 minutes prior to transfer to an operating room. Data collected included injury severity score (ISS), ED and hospital lengths of stay, and mortality. Continuous data, which were not distributed normally, were analyzed using Wilcoxon nonparametric analysis. Categorical variables were analyzed using chi-square testing. Multivariate logistic regression was used to account for confounding variables and isolate the effects of transport mode on mortality. Alpha for all tests was set at 0.05.

RESULTS

272 patients were eligible for study; 168 air medical and 104 ground transports. No between-group differences were found for ED length of stay, ISS, or mortality. A significantly longer hospital stay was found for air-transported patients. Subgroup analysis of patients with penetrating trauma and ISS of > or =25 revealed mortalities of 28% and 45% for air- and ground-transported patients, respectively; this difference was not statistically significant (p = 0.24), but the study had a power of only 22% to detect a difference at this magnitude.

CONCLUSION

This study failed to identify, but had insufficient power to rule out, outcome benefit to air medical transport in a subset of trauma patients requiring urgent operative interventions.